Refractometer



FIG. 1 is a right side elevation of a refractometer, showing my newdesign;

FIG. 2 is a left side elevation thereof;

FIG. 3 is a front elevation thereof;

FIG. 4 is a rear elevation thereof; and

FIG. 5 is a top plan view thereof.

The ornamental design for a refractometer, as shown and described.